Syringe with sterilization means



June 3, 1958 o. scHULLER Erm. 2,837,092

SYRINGE WITH STERILIZATION MEANS Filed Jan. 21. 1954 SYRINGE WITH STERILIZATION Otto Schller, Vienna, Austria, and Fred Malek-Naegeli, Berlngen, Switzerland Application January 21, 1954, Serial No. 405,469 Claims priority, application Austria January 23, 1953 s claims. (ci. 12s-21s) Sterilization of syringes used up to the present only is possible in their disassembled state through -boiling or heating. At-the moment. of applying the` syringe, how-v ever, such procedure does` not allord an absolute surety for sterility, since when assembling thesyringe, the piston and cylinder thereof may come in contact with air and.

perhaps with dust particles, and since through such manipulation germs and spores may enter the syringe.

The main object of our present invention is to provide a syringe which in the sterile state may be kept ready for application with greater security than thus far.

The syringe disclosed by ourpresent invention is distinguished by the fact that its piston comprises a hollow space for receiving a kgermicidal source of energy, such as a source of heat or ultraviolet radiation, or contains such source, and is made of a material which is resistant against the energy emitted from the source and permeable for such energy; the whole in such combination that the syringe in the assembled state is disinfectable :from the inside. It is, of course-possible to disinfect the syringe additionally and, if desired,'at the same time also from the outside. vr The piston may be a hollow body open at its rear end, in which is insertable the germicidal. source of energy for the purpose of sterilizing the syringe. It is also possible, however, to rigidly incorporate a germicidal `source of energy inthe piston. 'D

The material of the syringe piston advantageously is chosen heat-resistant or, respectively, pervious for ultraviolet rays. The piston may be made, for example, of quartz, ceramic material, Invar steel or of quartz glass or other refractory glass such as Pyrex, Tempax or Iena Instrument Glass.

Syringes having a cylinder made of quartz are known, which are destined dor the irradiation of blood from the outside with the aid of arsource of ultraviolet radiation. In the syringe disclosed in the present invention, however, irradiation may ltake place from the inside, which permits an immediate and better utilization of radiation, whereas when irradiating from the outside, only a fraction of the energy emitted from the source of radiation is utilizable, the major portion of such energy being lost through total reflection.

Several examples of the subject matter of the present invention are shown in the accompanying drawing, in which:

Fig. l shows a longitudinal section through a rst form of the syringe and through a device incorporating a germicidal source of energy inserted in the hollow space of the syringe piston,

Fig. 2 is a longitudinal section through a syringe piston of dilerent construction in which a source of heat is directly and rigidly built into the piston,

Fig. 3 shows the analogous illustration of a syringe piston having a rigidly built-in source of ultraviolet radiation,

Patented June 3, 1958 ICC Fig. 4 depicts a further example of a syringe piston alone in longitudinal section, and

Fig. 5 is a longitudinal section through a last formv of the syringe.

In Fig. 1, denotes the cylinder and 11 the piston of a syringe. The cylinder comprises a union member 12 for securing an injection needle to the cylinder. Piston 11 is formed as hollow body which is open at one end, i. e. at the end remote of union 12 for the injection needle. In order to prevent the cylinder from bursting when sterilizing the same, the piston consists of a material of which the coefficient of thermal expansion is smaller than that of the cylinder material. The piston, for example, may be made of quartz glass, quartz material, a heat-resistant ceramic material or of Invar steel, whilst the cylinder may be made of heat-resistant glass or clear rquartz glass. quartz material, and the cylinder of clear quartz glass,

which is best suited therefor on account of its small cof efficient of expansion.

As shown in Fig. l, piston 11 is mounted over a finger- I like peg 13y which comprises a germicidal source of energy such as a source of heat or of ultraviolet radiation,

and is secured to a cap 14. In the latter is provided an electric plug connection 15. A cover 16 is mounted over4 the syringe and is detachably secured to capv 14 by means i of a .bayonet catch 17. Cover 16, in a form of invention retains as much as possible the heat or radiation emitted i from peg 13.

In the cover is disposed a heating coil 18 surrounding cylinder 10 and being connected to plug connection 15. The heating coil, however, may be,

omitted.

Sterilization of syringe 10, 11 is carried out as follows. It peg 13 comprises a source of heat, piston 11 and cylinder 10 are heated thereby until the germs and spores are charred or incinerated. Such germicidal action may additionally `be `boosted yet from the outside by means ofv heating coil 18. In order to speedily cool off the syringe, the entire assembly including cover 16 may afterwards be immersed in cold water.

If peg 13 comprises a source of ultraviolet radiation, the germs and spores on piston 11 and cylinder 10 are killed olf through such radiation. In this case, at least the piston 11 has to be made of a material which is pervious for such radiation, for example of quartz material or quartz glass. The sterilizing action at the same time may be boosted from the outside through heating coil 18.

Instead of providing a particular peg 13 over which the piston 11 is mounted, a soucre of heat may be rigidly built in the hollow space of piston 11 directly, as shown in Fig. 2.l To such end, an insulating tube 19 is provided in the piston, on which is coiled a heating wire 20. To the rear end of piston 11 is secured a cap 21 made of insulating material and comprising a pair of connecting contact elements 22, which are connected to the heating wire 20. Cap 21 also serves as handle for actuating the syringe.

To sterilize the syringe, cap 21, similarly as the cap of a radio tube or incandescent lamp, is mounted in a holder to render possible the supply of current to heating coil 20. As in the rst form of invention described, sterilization here also is carried out in the assembled state of the syringe.

As shown in Fig. 3, a source of ultraviolet radiation is fixed directly in the hollow space of piston 11. To

' such end, the latter itself is formed as low-pressure mercury-vapor discharge tube and comprises a rodlike elec- Preferably, the piston is made of' j l 3 trode 23 and a gridlike electrode 24 which surrounds electrode 23. To connect the electrodes, again contact elements 22 are provided in an insulating cap .21 as in the,last Vexample described..v Since a` low-'pressureV discharge tube causes no substantial heating, the syringe aftersterilization'is quickly ready for application.

In conventonal all-glass syringes, the pistonr has the same diameter over its entire length and conforms to the inner wall of the cylinder, as shown in Fig. 1. When replenishing the syringe, the aspirated injection liquid wets the piston over its entire length owing to capillary action.

When withdrawing the piston, germs from the air may' settle thereon, which in the case of somewhat extended injections, `which for example may last ten minutes, might rediiuse into the injection liquid. In order to eliminate such risk also, the piston, as shown in Fig. 4, is provided with a peripheral neck 25 in which may colL lect the liquid owing through capillary action along the Apiston head. That p'ortion of the piston which is situated rearwardly of neck 25, then is not wetted by the'injection liquid.

v For the .same purpose,I a piston shank 27 of reduced diametern and cross-section relative'to` the piston headis formed by a shoulder 26 on piston 11, as shown in Figs. 2', k3`and 5. In this casera safeguard may be provided against unintentional movement of piston 11 out of the cylinder 10, as shown inA Fig. 5. To such end, pegs 28'are rigidly riveted to a spring clip 29 and project through holes in the wall'of vthe cylinder rear-end portion. Said clipv surroundscylinder and pushes the pegs 28 against piston shank 27. The pegs 28 thus form stops coacting withfa piston shoulder 26 and may escape outwardly when the piston is entirely withdrawn from cylinder 10 by overcoming a certain resistance.

The injection Vsyringes described and shown atord the following advantages over syringes known so far:

Sterilization from the inside alfords a more intensive and quicker utilization Iof the germicidal action of heat or ultraviolet radiation. or the energy of the germicidal source of energy may be decreased.

The risk of introducing germs from the air into the syringe is practically entirely eliminated by reason of the fact that the syring can be sterilized in the assembled Thus the time of sterilization 4 state and the piston is provided with a neck or aishoulderecl shank.

What we claim as new and desire to secure by Letters Patent, is:

1. In an injection syringe having a cylinder, a hollow piston displaceable within said cylinder, and means for radiating energy disposed-within the hollow of said piston, said piston being composed at least in part of material transparentv to the energy radiated by said radiating means, whereby said cylinder together. with a liquid when contained therein may be disinfected in assembled state without removal of said piston.

2. In a syringe according to claim 1, said piston cornprising a tubular member having a closed head normally seated in saidcylnder and having an open end opposite said head.

3. In a syringe according to claim 1, said cylinder being composed of a material resista-nt to the energy radi ated'by said radiating means, the thermal coeicient of the material 'of which said cylinder is composed being greater than the` thermal coefcient of the material of which said piston is composed.

4. In a syringe" according to Iclaim 1, saidpiston having a head portion 4conforming to the inner wall of said cylinder and a shank portion of reduced cross-section relative to' said head' portion, whereby said shank porl tion is maintained out of contact with said inner cylinderv wall. o v 1 5. In a syringe according to claim l, the hollow of said piston being seale'dioi and being filled with agas, said radiatingrmeans including electrodes for activating said gas to radiate energy, whereby disinfecting is eiected by electric gas discharge initiated within said piston.

References'Cited' in the tile of this patent UNITED STATES PATENTS France May 18, 1912 

